This invention is directed to light collecting and directing devices and, more particularly, to light collecting and directing devices suitable for use in photoelectric readers.
As will be readily understood by those familiar with the data processing arts, photoelectric readers are devices for "reading" the presence or absence of holes in an information medium, such as a punched tape or a punched card. As the tape or card is moved through the photoelectric reader, the presence or absence of holes are detected by directing a light beam or beams toward the tape or card, preferably along an axis lying orthogonal to the direction of movement of the tape or card. Light passed by the apertures is sensed by a plurality of light sensors mounted on the side of the tape or card remote from the light receiving side.
Photoelectric readers of the type generally described above have been utilized to read punched tapes and cards in various types of information processing systems. In addition, they have been utilized in various types of control systems such as N/C control systems and in vertical format units (VFUs), used to control the movement of print forms through a printer. That is, VFUs are used to control the vertical location of print on forms so that the information to be displayed is automatically printed at the appropriate locations on the forms. Normally, a tape is punched with a program that corresponds to the particular form to be used, or more than one program is punched on a tape and used in conjunction with a plurality of forms. In any event, since the VFU tape program controls the movement of the form through the printer, it controls the vertical location of print on the form.
In the past, various types of light sources have been used and proposed for use in photoelectric readers. They have included complex arrays of mirrors and prisms, line filament lamps, and light pipes, for examples. While light sources of the type proposed by the prior art have been generally satisfactory in many environments, they have certain disadvantages making them unsuitable for use in other environments. In this regard, they have been found unsuitable for use in photoelectric readers having a very limited amount of physical space within which the light source can be mounted, particularly those wherein cost is a primary factor. That is, many prior art photoelectric light sources are unsuitable for use in photoelectric readers where physical space is very limited. Those suitable for use under such conditions are more expensive than desirable.
Therefore, it is an object of this invention to provide a new and improved inexpensive light source suitable for use in a photoelectric reader.
It is a further object of this invention to provide a new and improved light source for producing a narrow strip light beam.
It is a still further object of this invention to provide an inexpensive, small light source suitable for use in a photoelectric reader to provide a narrow strip light beam.
It is yet another object of this invention to provide an improved photoelectric reader including an inexpensive, small light source adapted to produce a narrow strip light beam.